Beyond the Vault
by farfromdaylight
Summary: In this world, Shinra discovered nuclear power instead of mako, and drained the world's resources until nuclear war became inevitable. A hundred years later, someone is breaking into the underground vaults where survivors took refuge from the disaster. Two survivors collide in Cosmo Canyon, and set out to find out who's behind these attacks, uncovering a mystery in the process...
1. prologue

**Note:** An important note! I've been working on this fic since 2014, and the first draft is complete. Buckle in: this is a long fic, and you're in for quite a ride. Chapters will be added as I edit them, which will at times be a slow process. I recommend following this fic on AO3 if you can; this is only a crosspost.

* * *

War. War never changes.

Human history is written in countless battles for resources and power. Shinra did it for the wealth. Wutai did it out of necessity. Even the Ancients, whom humanity has come to revere as the epitome of all that is good in the world, turned brother against sister and mother against son when the calamity fell two long millennia ago.

But war never changes.

In the late 19th century, the discovery of nuclear power changed the weapons company Shinra Manufacturing Works into a world power overnight. Over the next century, the Shinra Electric Power Company would come to dominate every aspect of life on the Planet, from the electric power it brought to every home to the protection it offered through its army.

In this world, mako was nothing more than an addictive substance used to market soda; magic and materia were scarce, considered more myth than truth. The Shinra Electric Power Company built nuclear reactors in one city after another, bringing with them the spread of electricity, modern technology, and culture. Shinra scientists used atomic energy not as a weapon, but as a power source.

Yet as the new millennium drew near, the world's resources began to run out, and peace evaporated. Shinra fought to defend its territory — and its resources — against all who who would take them, particularly Wutai, which had nuclear interests of its own. In time, relations between the two broke down, and the world teetered on the brink of total war. Fearing the worst, Shinra began converting its nuclear reactors into massive vaults — fallout shelters meant to house the population should the worst come to pass.

In the year 2000, a meteor appeared in the sky. Its appearance would be the harbinger of the end of days.

Shinra reported that the meteor would do no more than cause mild climate change should it hit. Few civilians ever heard that broadcast. The last vestiges of peace had evaporated under the meteor's fiery glow. Riots erupted as people clamored for what few resources the planet had left to spare. Those who could fled to the vaults. But whether the meteor ever hit, none could say.

For in the midst of this chaos, one nation fired upon the other — and the Planet burned.


	2. one

Nibelheim was still weeks away.

It was in the mountains, far to the north, if the maps in the vault had even been right, and at this point he wasn't sure of that much. But now, it might not matter. He raised his hand to block the heavy midday sun out of his eyes, but it didn't do much good. He couldn't deal with this heat. Back home, when they'd first gotten out, any sunlight had been a shock. Over time he'd gotten used to it, maybe even come to like it over the fluorescent lights. But this dry heat — he couldn't handle it. His sweat had soaked through his heavy shirt, and his breath came in short, shallow pants.

The ground beneath his feet was barren and dry. There were no weeds in the cracks running along the ground. He couldn't remember the last time he'd even seen a plant. Only rocks and dust.

He looked up at the long stairway and the buildings he could see up on top of the cliff before him. The stair was the only way he could see up to the town; it was a sheer drop off either side.

He knew he didn't have the strength to get up there. The last of his water had run out that morning. Same with his food. He could hardly bear the weight of the sword on his back. Climbing a thousand stairs just to get to this village was out of the question.

They were probably going to shoot him on sight, anyway. If anybody was even home. He didn't know what he'd do if it was another abandoned village.

 _This sucks,_ he thought, and started up the stairs.

There hadn't been a cloud in the sky all day, and he could swear he felt the sun burning his skin off as he trudged forward, one step at a time. He'd been lightheaded since he woke up this morning. He rubbed at his eyes. Everything was so _fuzzy_.

He wasn't sure how far he'd made it up, but it wasn't like the thing had _railings_ , so he wasn't about to look down. Or sideways. He already wanted to stop and rest, but he refused to let himself. He was gonna get up there or die trying. He'd come too far for this.

Damn, he regretted drinking all that water right about now. He really, _really_ hoped this place wasn't a ghost town.

His sword clanged against his back as he climbed, sounding out a pattern. _Don't stop, don't stop, don't stop—_

His vision was too blurry to see anything but the stairs in front of him by now, but he didn't care — he didn't need to see to focus on the repetitive motion of putting one foot in front of the other, of hauling himself _up_ , one step after another. He didn't know how far up he was, or how close to the top, so that when he did reach the top, he was still moving on autopilot.

And he promptly passed out, sapped of strength.

* * *

She tended to hum while she worked.

It was a bad habit, and no matter how many people pointed it out to her, Tifa could never bring herself to stop. She would be tidying up the pub, wiping down the counters or cleaning up after a customer, and before long someone would tell her to knock it off. She'd smile and apologize, but before long she'd be at it again.

Today no one could hear her over all the activity in the pub. A caravan had come in from Corel earlier that morning, and while the merchants were all off trading their wares, the mercenaries hired to protect them had settled in at the pub for the duration.

"—and then I shot 'em right in the eye!"

Laughter filled the pub. Tifa caught snatches of the conversation as she worked, but it was hard to follow any one thread. From what she gathered, the trip hadn't gone as smoothly as the caravaners had hoped, but it had kept the mercenaries busy.

"Two more beers down here!" one of the mercs called.

"Coming right up!" Tifa pulled down two warm beers and set them on the counter. "Eight caps."

The merc pulled a handful of bottlecaps out of her pocket. Tifa made a quick count, then dumped them into the register. They were doing good business today; she would have to empty the till soon.

The door behind Tifa swung open, and Delia, the pub's owner, emerged, her arms full of plates. She pushed past Tifa, setting the plates down on the counter. "Order up! Who had the gecko steak?"

There was some commotion as food was doled out among the mercenaries, but once served they fell quiet, devouring their food. One merc didn't join the others but remained at the counter with his drink. "Aren't you hungry, darlin'?" Delia asked.

"I'll eat later," the man said. "Don't really have an appetite."

Tifa looked at him, curious. He was dressed as the other mercs were — combat armor, a shotgun slung on his back and a pistol on his hip — but he had barely touched the whiskey he'd ordered. Tifa wasn't sure why, but Delia seemed to understand. "Rough road?"

"Yeah," the man said. "We... we ran into raiders."

Tifa turned away and started cleaning the glasses by the sink.

Every caravan that came through Cosmo Canyon had stories about the raiders. They were the reason these mercenaries were celebrating their safe journey. If it weren't for the raiders, it would be easier to travel through the wastes. If it weren't for the raiders—

If it weren't for them, Tifa wouldn't be here at all.

"We were almost to Midway," the man said. "They came out of nowhere — yelling and screaming like nothing I'd ever heard. Before I knew it they were attacking, and—" His voice broke off, and he looked down at the counter.

"Drink up, son," Delia said. "You made it through, and that's all that counts. Now you just sit and take all the time you need, you hear me?"

The man took a gulp of his drink and nodded. Delia smiled and squeezed Tifa's shoulder. "You let me know if we get any more orders, alright darlin'?"

"Sure thing," Tifa said.

Delia headed back into the kitchen and Tifa returned to wiping down the glasses. There wasn't that much point to it, given how hard it was to get the grime off of anything out here, but Delia always insisted that they make the effort; it was important to keep up appearances. If the place looked nice and tidy, it made people feel better.

It was a moment before she realized the man at the counter was staring. Tifa glanced up and caught him looking at her arm with interest. "You've got one of those thingys," the man said. "Those computer things. Where'd you find it?"

"It was a gift," Tifa said with an easy smile. Easy because it was the truth. Easy because she'd answered it a hundred times before. Easy because she didn't want to think any further about it.

"Really?" The man's interest grew. "Most people who have those things don't just go givin' them away, you know. I've seen 'em go for thousands of caps in Corel."

"Guess I got lucky, then," Tifa said, sharper. The man raised an eyebrow, but didn't comment further.

Even so, Tifa couldn't fault his curiosity. She knew how valuable the bulky device around her left arm was. It was one of the rarer pieces of technology still existing in the world — a PHS, Personal Handsfree System, a wearable computer and radio, with a flashlight and built-in Rayleigh counter, the last of which was invaluable in the irradiated wasteland.

Tifa looked down at the device. She kept notes on her PHS, including her chore list for the pub and a couple of the lessons Master Zangan had taught her, but lately she'd found herself wishing she had something from her father stored in it. Over the past three years she had had a lot to regret, but what she'd come to regret the most was that she had nothing from her father. Nothing but the memories.

Had it really been three years? Already so many of her memories had faded. Her life was so different now, and the most difficult thing was that she enjoyed it. She had come to love Cosmo Canyon as a second home, and she cared for the people here. Life here was different, and harder, but it wasn't all bad.

Tifa shook her head. She didn't have time to stand around thinking about the past. The mercs were starting to clear out, and she needed to clean up after them before the merchants came in to eat. She had just come out from behind the bar when the pub door clattered open.

"Welcome," Tifa called out automatically. Her eyes widened; the two guards normally posted to the front gate were coming in, carrying a man between them. He was unconscious, his limbs dangling between them, head limp.

A red-furred creature entered the pub behind them. To most eyes he would seem like a mutated wolf or coyote, but to the residents of Cosmo Canyon he was their guardian and their leader, Nanaki. "Tifa, water, please," the beast said, and Tifa broke out of her stupor and started rummaging for the bottles of water they kept behind the counter.

She came over to the man; the guards had hauled him up onto one of the tables she'd been cleaning. "Who is he?" Tifa asked, handing the water over to one of the guards.

"No idea," one of the guards said. "Never seen him before. He didn't arrive with the caravan."

Two other Cosmo residents came in, and to Tifa's astonishment they were carrying a sword almost as tall as her, barely able to withstand the weight between them. "Leave it there," Nanaki said. At Tifa's look, he gave a shake of his head. "He was carrying it."

Tifa looked back at the man, taking in his sunburned features. He had dark hair that spilled over his shoulders. Sweat had soaked through his clothes — some kind of sleeveless knit sweater, pauldrons on both shoulders, suspenders, and thick leather pants. What was he thinking wearing such clothes here? No wonder he'd passed out. Her eyes traveled back up to his arm, and Tifa gasped as she caught sight of the device strapped on his arm — a PHS.

The clothes were familiar, like an itch at the back of her skull, but the PHS — he had to have come from —

The man coughed, swallowing down the water. He groaned, starting to wake up, and Tifa leaned forward to get a better look as the man's eyes opened, glowing in the dim light of the pub.

 _That glow — it's just like the raiders —_

"Please," the man croaked out. "I have to get to Nibelheim."


	3. two

"Are you sure?" Nanaki asked again.

Tifa looked at the stairs. The guards had carried the strange man up to the Shildra Inn, located above the pub. He had passed out on the table after his words, having used the last of his strength to speak to them. The town doctor had been called to treat him, and a faint buzz of excitement still threaded through the pub. It was rare to get travelers outside of the usual caravan runs between Corel and Cosmo.

But Tifa knew he wasn't just some traveler. Not with what he'd said. And not with what he was wearing.

She didn't have to see him again to know that the man's clothes were the same as those in her memories. The raiders had had guns, not the enormous sword that was still resting against the wall, but the rest matched up.

And they'd had the same eerily glowing eyes.

Tifa let out the breath she'd been holding. "I'm sure," she murmured. "It's the same. He looks just like the raiders who attacked us."

Nanaki rumbled low in his throat, a sound Tifa knew to be one he made when he was in deep thought. "Yet he has a PHS."

Tifa glanced down at her wrist. "I know."

That was the part that didn't add up. It was one thing for one of the raiders who attacked her home to show up all the way out in Cosmo Canyon. Having a PHS threw that into question. Each PHS had a biometric lock, which meant that they could only be removed by the person wearing it, or a highly skilled technician. They couldn't be easily stolen, even if the wearer was killed. No raider had that kind of training.

Nanaki gazed at Tifa with his one yellow eye. He had lost the other defending the village years ago. "You are aware of how things are dealt with here," he said.

"I..." Tifa had to swallow to find her voice. "Yes." She thought back to how she had first arrived in Cosmo Canyon. "I remember."

Though Cosmo Canyon had had dealings with the people of Corel for years, they weren't in the habit of taking in refugees. Cosmo was a remote village where every resident had to pull their weight in order to get by. But Tifa had had nowhere else to go after her home had been overrun. They had given her a chance, and she had repaid their kindness with hard work.

It was just...

Tifa looked up towards the inn again. If this wasn't one of those raiders— but what else could he be, even with a PHS? It didn't make any sense.

Was she strong enough to give him the benefit of the doubt?

Nanaki was still watching her, patient, and Tifa let herself take a breath, remembering Master Zangan's teachings on how to steady herself. She'd come here full of anger and hate and wanting nothing but revenge, and while Master Zangan hadn't belittled her those feelings, he had helped her to channel them into her training, to make them constructive instead of destructive.

"Okay," Tifa said. "I — I can't promise I'll see past everything. I'm not perfect. But I can listen to what he has to say."

Nanaki nodded. "Thank you. I know this is difficult for you. However, it is my hope that we will learn much from him, whatever it is he has to tell us." He stepped away, heading towards the bar. "Still, it will likely be quite some time before he recovers enough to speak with us. You should eat something."

Tifa gave him a weak smile. "I'll try."

* * *

Tifa and Nanaki relieved the guards in watching over their visitor several hours later. The Shildra Inn only had a few rooms for guests, as it was built directly into the canyon wall, but it was easier to reach than the doctor's house, which was up several flights of stairs and a ladder. Most people who got injured on the road to Cosmo Canyon ended up here.

The doctor had already come and gone some time ago; according to the guard, the man had no serious injuries, and was simply recovering from severe exhaustion. By the looks of him, Tifa guessed that he'd been in the canyons for weeks. No wonder.

Seeing him again, Tifa couldn't help but frown. She didn't recognize the man, she knew that much — not that she could have, if he really was one of the people who attacked her vault. They'd all been wearing helmets.

"You've got something on your mind," Nanaki said.

Tifa shook her head. "It's nothing."

She could stand here and wonder all she liked, but it wouldn't give her any answers. All she could do was wait.

It was another hour before a groan came from the bed. The man was starting to stir. He still looked worn out; it was the look of someone who had been traveling a long time and still had a long journey ahead of them. Tifa had seen it on plenty of caravaners.

She hadn't been mistaken. His eyes glowed. It was easier to make out in the room's dim light; his blue eyes had a faint green sheen. It made them look luminescent.

"Where am I?" he mumbled, looking around blearily.

"You have reached the settlement of Cosmo Canyon," Nanaki said.

The glow settled on Nanaki, and the man's eyes widened considerably. For that, Tifa didn't blame him; Nanaki was a lot to take in. He looked at Tifa; it was as if he were asking her if this was real. Then he rubbed his eyes. "Okay, uh," he said, "either I'm still dreaming or that mutant dog just talked a minute ago."

"I'm not a dog," Nanaki sighed. He was used to this reaction. Tifa had reacted in much the same way when she first arrived. It was hard to take in a sentient beast, even one as patient as Nanaki. "I am the guardian of Cosmo Canyon, Nanaki, son of Seto. This is my natural form."

"You're... really talking." He gaped at the beast for a moment, then laughed, breathless. "You know what, sure. I'll buy it. Not the weirdest thing I've ever seen. Nice to meet you, Nanaki. I'm Zack Fair, of Gongaga."

 _That_ wasn't what Tifa was expecting to hear.

No one had heard anything from Gongaga in a hundred years. People had gone looking for its vault, but no one had ever found any sign of it. People told stories about those who claimed to find it, but no one had ever provided any proof of the _real_ Gongaga. It had become something of a myth in this region: the lost vault of Gongaga, swallowed up by the jungle, never to be seen again.

This had to be some kind of trick, didn't it? " _Gongaga?_ " she repeated. "But that's— that can't be possible."

Zack looked back to her and took in the PHS on her arm, eyes widening. "Wait— you're from a vault too? Did they have a vault here?"

Tifa opened her mouth to reply, but before she could, Nanaki cut her off. "We'd like to hear your story first, please," Nanaki said. "Can you prove that you're from Gongaga? We have not seen anyone from Gongaga since before the war."

"Sure, no problem," Zack said. He unlatched the PHS and removed it from his arm. Inside, near the hinge, was a small inscription in raised letters:

Personal Handsfree System Model 3000 Mk IV  
Manufactured by RobCo Industries  
for Distribution by Shinra Electric Power Company  
GONGAGA VAULT

Tifa stared at the words. This... this was proof. No one could fake a PHS; it was rare technology not manufactured since the war. They had only been distributed to vaults. She watched as Zack put the device back on and the screen lit up. It was real.

But if he was really from Gongaga, then... what did that mean?

"It seems you're telling the truth," Nanaki said. "However, there is much that still needs to be answered. When did your vault open? How long was it sealed?"

Zack let out a heavy breath. "Yeah, I guess it all starts with that, huh? When the vault opened. I was born in the vault, and when I was a kid, I thought we were never coming out. We had enough supplies to last for a long, long time. Or that's what we were told." He snorted. "What they weren't telling us was that our vault was slowly breaking down. Eventually, it couldn't hold out anymore, and neither did our supplies. We were forced to evacuate in 2100."

The timing sounded about right, as far as Tifa knew. Master Zangan had been one of the people who searched for Gongaga when he was younger, he'd told her, but that had been many years ago. Over time, the story had lost its luster, and these days hardly anyone thought Gongaga was still worth finding. There hadn't been any expeditions to find it in the past decade.

"See, getting _out_ wasn't so bad," Zack continued. "There were some monsters and mutated animals outside the vault, but we had lots of weapons stocked up, and we'd done some drills for that. We were pretty much ready. What went bad was getting the supplies out of the vault.

"The Overseer and the tech guys had already figured out that we couldn't keep living inside the vault. All of the systems were going bad and losing power. The air filtration system was broken. We were running out of water. We barely had any food left. So the plan was to move back into the village and try to fortify it with supplies from the vault. We got about half of it out when our nuclear reactor gave out."

"Oh no," Tifa breathed. The dangers of a reactor meltdown had been drilled into everyone in her vault; it was a constant worry.

Zack grimaced. "The reactor was already on its last legs, but whoever built it — I dunno what they did exactly, but they set it up so that instead of going into meltdown and blowing everything up, it just shut the reactor down and put the vault into lockdown. Except, well." He rubbed the back of his head. "Some of us got caught inside. The vault door closed automatically, and I — we couldn't get out. The people who were down in the reactor level when it locked down... they were mutated. Changed into these horrible creatures. They— they weren't human anymore. And we had to..." He broke off. "Sorry. Kinda try not to think about it."

"It's okay," Tifa said.

"Is that where you got the glow in your eyes?" Nanaki asked gravely.

"Yeah, well, after getting trapped in an irradiated vault for close to a week, it kinda sets in," Zack said. "We managed to barricade ourselves from the lower levels, but we still ended up with heavy radiation poisoning. In the end, they had to break down the vault door to get us out. Only three of us survived. Me and my two best friends." He looked down at his lap. "Angeal and Genesis."

Zack was quiet for a moment, clearly recalling painful memories, and while both Tifa and Nanaki could commiserate with that, some things didn't add up. "There's more that I'd like to ask," Nanaki said. "Those clothes you're wearing, for instance—"

"Yeah— yeah, sorry," Zack said. "It's a long story and — well, some of it might sound crazy. But it's all true. And it's why I need to get to Nibelheim."

Tifa bit her lip. She hadn't missed the way Nanaki cut her off earlier, and she had a feeling that the beast wanted to get everything he could out of Zack first. She didn't disagree with that, but it was hard not to ask Zack everything on her mind. "We'll listen," she said. "Just start at the beginning."

Zack gave her a weak smile. "Well, after we got out of the reactor, the three of us were... different. There's no other way to describe it. We were faster, and stronger. I mean, when we were trapped in the vault, we'd had to fight against the ones who got really mutated. There was no way to survive otherwise. But the radiation, well... it changed us. That's the only way to put it. And it made the other people from the vault afraid of us.

"That was when we started training. We figured that if we were stronger, then it was up to us to protect the village. Gongaga is dangerous; every other day we were getting attacked by the monsters in the jungle. We had to ration our ammo, so we started training on the old swords they'd had down in the vault—" Zack cut himself off and looked around wildly. "Where's my sword? Did I drop it?"

"No, it's downstairs," Nanaki said.

Zack looked at him for a moment, as if considering whether he were telling the truth, then nodded. "Alright. So anyway, when we started using swords, it got easier. You've gotta have a good blade, and we went through a lot of bad ones, but it's better than running out of ammo against a gagihandi."

"A what?" Tifa asked.

"Gongagan lizard that turns you to stone. You gotta stab it in the eye. Like I said, you wanna have ammo."

"...Right." She wasn't even going to ask.

"Anyway..." Zack pulled at his shirt. "Things were going okay. We kept the village safe. We made sure the monsters stayed out. Not everyone liked us, but I had Angeal and Genesis, and they had me. Wasn't anything like being in the vault, but it wasn't all that bad either." He swallowed. "That's when the airship crashed."

Nanaki's jaw dropped. "That's _impossible_. Who could even— how—?!"

Zack shook his head. "I don't know. Whoever they were, they weren't trying to get to _Gongaga_ , that's for sure. The airship was already in bad shape when it crashed, we saw it way in the distance before it crashed in the jungle. It was full of soldiers and robots." He smiled, humorless. " _They_ had ammo.

"They took over the village within a day. They took some people as laborers to work on repairing the airship. The rest they assigned to the reactor. And as for me..." Zack pointed as his eyes. "They had this scientist who wanted to know where I got these. Same with my friends, Genesis and Angeal. He locked us up and did tests on us."

"When was this? What year?" Tifa asked. If this was true — if _this_ was where the raiders had come from who attacked Nibelheim, then—

"2102," Zack said. "They crashed in March. They finished the repairs in 2104. I got left behind, along with a bunch of scientists who kept doing tests on me." His words were coming out faster now, as if he couldn't keep them bottled up inside, and desperation crackled in his voice. "I've been locked up for the past three years. It wasn't until a couple months ago that I managed to break out. There weren't that many soldiers left, or scientists. Me and the villagers managed to take them all out. That's when I found out they were heading for Nibelheim."

Tifa felt dazed. It added up. Verifying his story about the airship wasn't possible, but deep down, she _knew_ it was true. The attack on Nibelheim had happened in 2104, but she'd never thought past her own home. Never imagined that the raiders could have attacked _other_ vaults. She'd thought all they wanted was the supplies. What if they were still _there?_

"That's why I have to get there," Zack said. "I was the only one left behind — I don't know why, I guess they were doing different experiments on me. But they took Angeal and Genesis with them to Nibelheim. They're my best friends in the whole world. They _have_ to be there. I know it's a long shot, but—"

"No," Tifa said. "It's possible." She met Zack's eyes. "Because I escaped Nibelheim on the day it was attacked."


	4. three

When Tifa thought back, her first thought was always of the diner.

Sure, the diner itself wasn't much to look at. The floor was scuffed from all the people who went through it on a daily basis. Johnny and Evan were always putting prank messages up on the bulletin board. The cushions on the red seats had gone flat a long time ago. The lights flickered sometimes. And it wasn't like the four metal walls were much to look at.

But after all the time she'd spent there, it was home.

Only a few people had come to the vault diner that night. Some people had hated the job the G.O.A.T. gave them, but Tifa had never minded being the apprentice Fry Cook. She got to see just about everyone every day, and she got to hear how things were going throughout the whole vault. And besides, she enjoyed the work. She had always enjoyed cooking, and it was fun trying out new recipes.

Of course, she'd be doing it for the rest of her life. Tifa supposed she was lucky to have gotten something she liked. You couldn't change your assigned job once you got it. The G.O.A.T. was for life. So was being in the vault.

"Good work today, Tifa," Mireille said. The old woman had been the vault's Fry Cook since Tifa was born, and though at times she was strict with her, she was always fair. "You run along home to your father now, you hear? You've done enough here today, girl."

"Okay, Mireille," Tifa said, hanging up her apron on the post behind the counter. She stuck her hands in the pockets of the vault jumpsuit and headed out towards the atrium. Most people lived in the residential sector of the vault, around the other side and down a flight of stairs, but Tifa lived in the Overseer's quarters with her father.

"Oh, Tifa!" Tifa turned back; Mireille was calling out to her from the diner, a bag in her hand. "I almost forgot, I made these cookies for you and your father this morning. Mercy me, I almost let you go on without them!"

"What were you telling me about rations this morning?" Tifa asked, but she couldn't help the beam on her face.

"That the Overseer might lighten up on them if he was in a good mood," Mireille replied with a wink. Tifa laughed and took the cookies. "You get those to your daddy right quick, you hear? I put lots of—"

A shrill alarm cut her off, and the light in the hallways flickered. Tifa froze. She'd only ever heard that alarm in the yearly emergency drill. They weren't supposed to have another drill for _months_.

"Well, isn't this the strangest thing," Mireille said, looking around.

A cold dread trickled down her spine. "What's going on?" Tifa said aloud.

"Oh, honey, I'm sure it's nothing. Why don't you go find your father? I'm sure one of the boys just set the alarm off as some silly joke." Mireille patted her shoulder. "I'm going off to bed. You take care now."

Mireille headed down the hall towards the residential quarters while Tifa turned towards the atrium. Something was wrong. She couldn't say why she knew it, or how. The boys had made their share of trouble before, but no one would dare to set off the emergency alarm. Not even Evan and that new gang of his would do this.

The alarm was still blaring in her ears, but through it, she heard something loud and sharp. It took her a moment to realize it was gunfire.

Tifa rushed out to the atrium; the diner was on the second floor, overlooking the open area below. Whenever her father held meetings for the whole vault, they'd gather there and listen to him. She looked down and saw two bodies below — bodies in vault jumpsuits — bodies covered in _blood_ , she could make out their faces, it was Evan and Leslie —

There were people pouring in through the front entrance.

The vault had been breached.

Tifa screamed.

"Up there!" someone yelled, and Tifa didn't think, she just ran, gunfire spraying the metal walls behind her. She had to — she had to — she couldn't even think, she was so scared, but they'd — they'd drilled for this, right? What To Do If The Vault Is Breached By The Enemy, they'd gone over it in school, there were slides on the projector and Ms. Annette had talked about in her droning voice and Tifa had doodled in the margins of her notebook because she was bored and of course the Enemy, whoever they were, were never _really_ going to attack their vault, that was ridiculous, wasn't it? Wasn't it, Ms. Annette? She remembered Kyrie asking that in class and Ms. Annette had said of course it was ridiculous, but they had to plan for it anyway.

The emergency drills had only ever been ceremonial, really. No one ever expected something like _this_ to happen.

Tifa ran and ran, not even seeing where she was going, but she knew the vault like the back of her hand and she'd run straight to the security sector, where the alarms were blaring louder than ever. The monitors were all on and some of the guards were staring at them, all dumbfounded that this was really happening, and her father was with them, hand still on the console that controlled the alarms.

Her _father_ — "Papa—" Tifa cried, like she was eight years old again, and rushed towards him. Her father turned towards her, breaking out of his stupor, and wrapped his arms tight around her. "Papa, what's _happening?_ Who are they?"

"We don't know," her father said, and there was something in the way he said it that made her look up at him. "They don't look like the Wutai, but—"

"Sir, they're heading this way," one of the security guards said — Mr. Brown, who always used to smile at her when she was little. "What do we do? The weapons they've got—"

"Hold the line here," her father said. "I've got to get Tifa out of here. Come with me, Tifa."

"Yes, sir," the guards chorused, each one looking more worried than the last. Tifa took her father's hand and followed him down the hall to their quarters. The doors slid shut behind them, and her father locked the door, then headed straight for the terminal in his office.

"Tifa, you've got to get out of here," he said. "I'll create a distraction—"

"What?" Tifa grabbed her father's arm. "What are you talking about—?"

He pulled her back and away from his desk, and to Tifa's astonishment, the desk itself rose up. His chair sank back, and a passageway opened up. It was an emergency exit, one she'd never known existed.

"You have to go," her father said. "Now, Tifa! There are supplies in the tunnel — don't let anyone see you, and get down the tunnel to the outside — the radiation levels should be low enough but check your Rayleigh counter just in case—"

"What are you talking about, Papa—" None of this was making sense. Tifa felt as though her head was spinning, and the world was going with it. Before Tifa could say anything more, her father pushed her down the stairs. "Get out of here, get as far away from them as you can," he said. "I'll make sure they don't follow you."

"No— no, Papa, please, _please_ , come with me! Don't do this!" She tried pulling on his arm, tried dragging him down into the passageway with her, but he was already closing the passageway behind her and pushing her back down into it.

"I'm sorry, Tifa," he said. "I love you, sweetheart— just run, run and don't let them catch you—"

The passageway closed with a metallic clank, and Tifa sobbed against it, pounding against it, trying to force it open again. Then there was a sharp noise and another retort of gunfire and the fear seized her again, and though she felt like a coward for it, she turned from the closed door and made her way down the stairs, terrified that they were going to find the passage.

She knew what had happened to her father — what they'd done to him — but she pushed it to the back of her mind, blocking it out and refusing to acknowledge it. She wouldn't let it be in vain. Not now, not ever.

Tifa reached the bottom of the stairs and turned her PHS light on. The first thing she saw was a radroach not three feet away from her, and she had to press her fist against her mouth to muffle a scream. She had seen radroaches before — they got into the vault sometimes and security always dealt with them — but _now_ was not the time she wanted to take one on by herself.

Worst of all, she didn't have a weapon. And it had seen her.

Radroaches were fast, but fear and anguish and sheer adrenaline were doing Tifa a lot of favors. She stomped straight on the radroach's head, and while she didn't crush it in one go — their exoskeletons were too tough for that — it was enough to stun the creature. She stomped on it again, and again, until it stopped moving entirely.

Tifa took a moment to catch her breath. _Okay. Okay. I can do this._

She waved her PHS light around the hallway. The light was sickly and greenish, the same as the display on the device itself, but it was bright enough to see by, and no one had ever installed lights in here. The hallway was narrow and cramped, about as much to be expected of an emergency tunnel, but there weren't any more radroaches, and Tifa decided to count that as a win.

She made her way forward and reached the end of the hall, finding an opening leading to another narrow hall. There was one radroach in the corner of this one, but Tifa walked over it and gave it a good stomp before realizing it was already dead. Fine by her.

She'd been so occupied by the radroach that she almost missed the box in the corner. Tifa was half afraid it'd be locked, but it gave when she opened it, and she shone her PHS light on the contents: a couple boxes of cram, two bottles of water, and a spare vault jumpsuit. She pulled the jumpsuit out and looked behind the boxes, but she couldn't find any weapons. Okay. Food was good. At least she wouldn't starve right away.

A fresh burst of panic bubbled up, and she did her best to squash it down. She could do this. She _could_.

At the end of this tunnel was a closed door. Tifa realized that she had to be close to the main vault entrance, where the sealed door was. She'd gotten a lot of her nerve back after killing that radroach, but the idea of opening this door to a whole group of people with guns was enough to make her freeze in her tracks.

They couldn't all be out there, she told herself. They had to mostly be in the vault by now. She could get out. She could escape.

She didn't want to. She wanted to turn around, run back up to her room, and hide under her bed. But she knew that wasn't an option. Whoever these people were, they weren't going to just give up and go away. She had to escape.

Tifa pushed the door open just enough to look out through. She froze as she caught sight of two unfamiliar people standing by the wide open vault door, a sight she'd never imagined to see in her life. They were facing away from her.

She pushed the door open further, and realized that the door itself was a hidden wall into the security booth in the entranceway. She looked down, and realized that the body of the guard was still there. It was Mr. Gould. She hadn't seen a dead person this closely since her mother died, and she felt a chill, looking at him. He'd probably been sitting right there at the guard station when they came in. Had he even known what was happening?

Wait — _Gould._

Tifa stared at him. Sure enough, Gould hadn't even had time to draw his gun. It was still holstered at his waist.

She'd never fired a gun in her life. She only barely knew how. But she knew she wasn't getting past those two guards without it.

Tifa pushed the door open as slowly as she could, desperate not to make any noise. She kept looking back and forth from the guards at the front entrance to the vault itself, worried that someone was going to come out and see that she was here. After a long, paralyzing moment, she got the door open, and she crept out into the security booth, setting the box of supplies down beside Gould's dead body.

 _Thank you_ , she thought as she pulled his gun out of its holster. He had a second case of ammunition in his belt; she stuck that in her pocket.

Tifa clutched the box of supplies to her side and held the gun tight. Nobody had come out from the vault, and no one else had come inside, either. She wasn't sure why the two guards were standing there, but she didn't want to stick around in case someone else _was_ coming. If this was the only chance she was going to get, she'd take it.

She crept out from the security booth and stayed low just in case they turned around. She hid behind one of the massive machines that powered the vault door, out of the line of sight of the guards. She just had to get past them and get out of here.

Right. She wanted to laugh. Not twenty minutes ago Mireille had been giving her cookies. Now Mireille was probably dead, and so was her father, and everyone she'd ever known—

"Entrance team, report."

Tifa nearly jumped out of her skin before she realized that the voice was coming from a radio one of the guards was holding. She froze against the machinery she was hiding behind. She didn't dare peek out and see what it was.

"All clear up here, sir," one of the guards said.

"Keep a sharp eye out. If any of them get up there, your orders are to shoot on sight."

"Yes, sir."

The radio clicked off, and Tifa knew she wasn't going to get another chance. They were going to kill her if she didn't escape, _right now_. She peeked up from behind the machine just long enough to see that the guards were moving away from the entrance and back towards the vault, right where she was hiding. This was it.

She'd never been so scared in her life. They had guns, big ones, and all she had was a tiny little pistol she didn't even know how to shoot. They'd kill her if she tried to take them head-on.

But—

But her father had died to get her out of here.

She had to make it.

Tifa scrambled backwards and pulled herself over the railing guarding the walkway from the vault door. She hid behind it as the guards passed by, knowing she only had seconds, but it was enough for them not to notice her.

The second they made it to the other end of the walkway, she bolted.

The sound was enough to alert them, and she heard the pepper of gunfire behind her, but the Nibelheim vault was built into a cave system, and the exit was a sharp slope upwards. Tifa ran up the hill as fast as she could, through the open door at the end, and out into the scorching daylight.

She'd always heard that it was bright Outside, that there was something called a sun that warmed the Planet, but what she never could have prepared for was the _sky_. There was so much emptiness up there that she was getting dizzy looking at it, and even though the jagged peaks of the Nibel mountains cut against the sky it wasn't enough to keep her from wanting to turn around and run back inside.

But she couldn't — she couldn't — she could hear someone behind her, and she didn't think, she just turned and ran, away from the vault, away from the intruders, away from everything.

* * *

"I don't know how I made it off the mountain. There were caves, and I lost the raiders, but the monsters... I ran away from every one I saw. The ones I couldn't run from, I shot, until I ran out of ammo. I just kept running. Eventually I got to the bottom and reached the town. I'd hurt my arm — a wolf attacked me — and I was exhausted. I don't know where I was exactly when Master Zangan found me."

"Zangan?" Zack asked.

"He was a wanderer from Cosmo Canyon," Tifa said. "A scavenger. He'd been doing it for years. He said he was heading to Nibelheim to see if there was anything valuable when he found me. I told him about the vault, and he decided to bring me back here, to his home."

"Wow," Zack said. His eyes were wide. "Tifa, the people who attacked your vault — they've gotta be the same ones who took over Gongaga! We've gotta go to Nibelheim!"

Tifa looked at his bright eyes and felt a burst of warmth in her chest, the kind she hadn't felt in years. She realized that it was _hope_. She'd given up all hope when she'd left Nibelheim for dead, but the thought that someone might have survived... that people might still be there... she couldn't bear the thought of not knowing. "You're right," she said. "If there's any chance, no matter how small — we have to go to Nibelheim. We have to help them."

"All right!" Zack sat up and tried to climb out of bed. "Let's get going!"

Nanaki pushed the man back towards the bed with one paw. "You're still dehydrated and exhausted," he said. "While I will do all in my power to aid both of you, neither of you are going anywhere until preparations are made. Including rest, Zack."

Zack started sputtering protests, and Tifa was tempted to agree with him, but deep down she knew Nanaki was right. She smiled at Zack and rose. "Come on, get back in bed," she said, and gave him a push of her own. "If we leave now, we'll just have to turn back around because you're wiped out. Get some rest, and I'll get you some more water, okay?"

Zack pouted, but he sank back into the bed. "Okaaaaay. But we're leaving first thing in the morning!"

Tifa wished that were true.


	5. four

While the observatory at the top of Cosmo Canyon had never been off limits to the villagers, people rarely went up to visit it. Its original owner was only remembered through stories and legend, but out of respect to Nanaki, who had loved Bugenhagen like a grandfather, they left the building alone.

Most of the equipment was no longer operable; while the windmills around the village provided most of the town's power, Nanaki had decided years ago that Bugenhagen's machinery wasn't vital enough for them to run power up to it. He had fond memories of Bugenhagen's incredible holograms, but he was happier seeing the people in the village with lights in their homes.

Still, the observatory was nostalgic for Nanaki, and when he wanted to think, he went up there. And he had much to think about. This was the second time he'd heard Tifa's story, and now with Zack's beside it, Nanaki knew that something would have to be done.

When Tifa had arrived three years ago at Zangan's side, exhausted and terrified from the long, arduous journey from Nibelheim, Nanaki had thought nothing of offering her shelter and letting her take refuge in their village. Yet while he had briefly considering sending scouts to her vault to investigate, he had soon dismissed the thought. The people of Cosmo Canyon deferred to his guidance, but they were by no means the protectors of the entire continent. He was sorry for Tifa's loss, and had no issue offering her support as she rebuilt her life, but they had neither the manpower nor the supplies for a long journey to the north to oust what he had believed to be nothing more than a band of raiders. Tifa had been traumatized when she'd first arrived; this second telling of her tale had been much calmer, stabilized by the passing of time.

More importantly, Nanaki had believed that the intruders had gone into the vault purely for the supplies. It was unfortunate, but not entirely without precedent. Raiders were common across the wasteland, and they attacked anywhere they thought they could find more. No, it was Zack's story that changed all of that. The idea that someone out there going into vaults and using the inhabitants for scientific experiments was truly worrying.

Cosmo Canyon hadn't had a Shinra vault; they'd never even had a nuclear reactor. At the time the Shinra Electric Power Company was spreading its influence across the world, Bugenhagen and the other village elders had rejected Shinra's proposal to build a reactor, and while Shinra hadn't liked it, the costs of building one in the terrain was far too high to be worth the effort. Cosmo Canyon had been a largely self-sufficient community during the troubled years leading up to the Great War.

After the Corel oil conflict, though, the village elders had seen the writing on the wall, and collectively decided to start preparing for what they saw to be the inevitable. They started clearing out the caves beneath the village, killed the wraiths haunting the Cave of the Gi, and sealed all of the exits. It wasn't as pristine as the Shinra Company's vaults, but when the war came, they had been safe.

"You look like you're thinking too hard."

Nanaki looked up. Another beast just like him had entered the observatory, flaming tail flicking back and forth. Her fur was paler than his, but decorated with just as many tattooed and scars. He huffed at Deneh and scooted over as she came over to lie down next to him. "Just remembering."

"Something good, I hope." She curled into his warmth with a purr; the downside of no power going to the observatory was that it was always cold as soon as the sun went down.

"No such luck, I'm afraid." Nanaki sighed and lowered his head onto his paws. "I trust you've already spoken to the elders?"

"Mm. Of all the ways for the Gongaga mystery to be solved." Deneh met his eye. "Tell me what you're thinking."

"I'm not sure I know myself." Nanaki sighed. "Zack's story is compelling. If it had any truth to it, it's something that needs to be investigated. Our defenses can repel raiders and monsters, not airships and soldiers."

"Do you believe him?"

"I believe his desperation." Though Nanaki had been listening to Zack's story in great detail, he had paid the most attention to _how_ Zack had told his tale. The man seemed to believe it; whether or not these friends of his had been taken to Nibelheim, Nanaki had no doubt in his mind that Zack would do anything to get them back. Whether all the details were as Zack remembered would remain to be seen. "Whether Gongaga is as he tells it, I don't know. We'll have to send someone."

"The elders said the same thing. Amani should go; she's been antsy hanging around here so long. She can take care of herself."

Nanaki nodded. "If she goes, Ivan will want to go too. They can take stock of Gongaga. As for Nibelheim..."

Deneh huffed. "Tifa is already packing. I imagine that boy will be the same. Cubs, the both of them."

"I can't blame them," Nanaki said. "You know that Tifa could never sit and wait. As for Zack, I believe the only reason he hasn't left already is because he doesn't know the way."

"Tifa isn't ready to make that journey alone," Deneh said. "She's still so young, and without Zangan..."

"I know," Nanaki said.

"And if Amani's going down south, there aren't that many others we can send with them. Kenelm will be wanting to shore up our defenses."

"I know, Deneh."

Deneh paused and looked at him for a long moment. Then she huffed out a laugh. "The elders will throw a fit, you know."

"I'll speak to them," Nanaki said. "If there's any truth to this threat, Deneh, we could all be in danger. I can not sit idly by, no more than I can let those two cubs try to find their way to Nibelheim unguided. I will show them the way."

Deneh chuckled, a rumbling noise that rippled through her, and rubbed her nose against his. "I wasn't arguing, Nanaki," she said. "You're right. You've been up to Corel enough times to lead them. I can manage the canyon well enough in the meantime. The elders have been around long enough to remember that."

That was true. Cosmo Canyon's elders weren't chosen for age but for experience. These days, the elders were more of a peacekeeping and security council than anything else, and they did their part to keep Cosmo Canyon safe from threats. Nanaki and Deneh served as the village guardians, and as such were part of all decisions made on behalf of the village given their long lives.

"Just promise me one thing," Deneh said. "You get to the bottom of this and make it back to me safely, all right?"

Nanaki smiled and rubbed his nose against hers. "I promise."

* * *

"—and Marie will cover the pub in the evenings, until nine," Tifa finished. "I couldn't get anyone for Wednesday afternoons, but it's always slow then. It should be okay."

"Well, haven't you got this all figured!" Delia said.

"Are you sure you'll be all right? I know this all came up suddenly, and—"

"Nonsense," Delia reassured her. "Honey, if you say you need to go back home, then you need to go back home. That's all there is to it. I can get by just fine here. Been doing it a long time before you came and I'll be doing it long after."

Tifa managed a small smile. "If you're sure. Okay."

She hesitated, and then wrapped her arms around Delia. A warm hug enveloped her. Tifa couldn't remember the last time she had felt this kind of warmth. Perhaps not since before her father died.

"You come home safe now, you understand me?" Delia said. "Nanaki'll look out for you. You stick close to him"

Tifa's eyes widened. She hadn't told Delia the whole story, only that she was going back in search of survivors. It didn't matter. She understood the danger.

Tifa squeezed back. "I promise," she said. "I'll come back."

* * *

Cosmo Canyon's graveyard wasn't in the town itself; you had to go down through the caves and out past the petrified statue of Nanaki's father, Seto. According to town legend, the caves had been haunted by one of their ancient enemies, the Gi, long before the Great War. These days it was an easy walk: the villagers had spent twenty years living down in these caves after the war, and still used them to this day for storage. Tifa herself came down through the caves regularly to retrieve supplies for the pub.

Tifa made her way down the twisting path with ease and came out on the other side of the canyon. Seto's statue stood at the top of the jagged cliff and below were the graves of the villagers, each memorialized by a small stone. Tifa walked down to the end, finding Zangan's.

"Master," she murmured, and bowed.

Tifa had started training with Master Zangan not long after arriving in Cosmo Canyon. She had been witness to his skill on the journey there and knew that anything she could learn from him would help her survive out in the wasteland. But that knowledge had not helped when it was her standing out in the canyon, approaching a gecko's nest.

Out there, armed with nothing but a pair of heavy gauntlets and a small pistol, there had been nothing between her and the creature's claws. And geckos were _fast_ , scurrying from one patch of shade to the next along the canyon walls. The gecko's nest lay deeper in the canyons, tucked in one of the caves, but one had been out in the open, and had spotted her as she drew close.

The gecko had come at her in a flash, its claws slashing across her leg, and she had panicked, her fist flying out to catch the side of its large head. Her punches had been sloppy, the weight behind them uneven, and the gecko had continued clawing at her knees. In desperation she had kicked at it, knocking it on its side, and with hurried stomps she had crushed its head.

It hadn't been like Master Zangan's clean, efficient kills. She had still been shaking with fear and adrenaline. Her legs had been scratched up, her shoes were covered in blood. But for the first time she had not needed protecting.

"Master," Tifa said, "I'm going back to Nibelheim. A man came here. His vault was attacked. He thinks there might be survivors at Nibelheim." Tifa exhaled. "I don't know what we're going to find. I just— I have to know, Master. I have to."

She looked down at her hands and slowly closed both of them into fists. "I know you said to let go of the anger, Master. And — I can't let go of all of it. I'm sorry. I just have to _know_. I hope you can understand.

"I promise that I'll uphold your teachings, Master. No matter what. Thank you."

There would be no answer, Tifa felt comforted in saying it aloud, and that was enough. She'd learned about the Lifestream since coming to Cosmo Canyon, and knew now that the dead didn't really watch over them, like her father had told her when her mother died; they returned to the Planet and became new life. Still, even if it wasn't how things really were, she couldn't help but cling to those childish beliefs if it meant they gave her strength.

Tifa walked back through the graveyard, intending to go back up to the village, but she was surprised to see another figure heading down from the caves. "I thought I'd find you here," Nanaki said, flaming tail flickering back and forth. He looked up at his father's figure with a fond look, then looked back to Tifa. "Did you finish saying your goodbyes?"

"Yeah." Tifa glanced back at Master Zangan's grave. She considered this to be more his place than the home he'd had back in the village. Her memories of that house were of his last few weeks, when he'd been in too much pain to wake.

Nanaki studied her for a moment, then nodded. "If you would wait a moment, I would like to share something with you."

"Sure." Tifa stepped aside as Nanaki headed up towards Seto's cliff. Nanaki leapt up with the ease of years of practice. He stood beside his father's stone form, and Tifa could hear him speaking to it, but didn't try to make the words out.

Nanaki was done after a few minutes, and it was then that she realized he had something strapped to his back. The artisans in town had developed a few different packs for Nanaki and Deneh over the years so that they could carry supplies on long journeys.

"Master Zangan asked something of me, not long before he passed," Nanaki said. "Though he hoped that you would remain here, he knew that one day you would come to leave Cosmo Canyon. He told me to give you this when that time came." Nanaki jerked his head towards his pack. "Please."

Tifa bent and undid the cord binding the pack. She withdrew a thin book with a black cover, embossed with the words "Final Heaven." She gasped. "This is—!"

Master Zangan had fallen ill before he had been able to teach Tifa the final move of his style of martial arts, which dated back to before the war. He had told her its name, but had not even begun its teaching before he was too weak to perform it. She'd never known that a book about it existed.

"But why didn't he give it to me himself? Why did he wait?" Tifa asked.

"More than anything, Tifa, Master Zangan never wanted you to have to use what he taught you," Nanaki said gravely, and she looked up from the book to see pain in his gaze. "He taught you what he knew so you would never have to fear for your safety, and so you could use what you knew to protect others. Which is why I pass this to you now."

Tifa's throat went tight. When she had first asked Master Zangan to teach her, it had been so she could survive in the wasteland. Over time, it had become something more. Tifa had never been content to simply survive out here. She wanted to live, no matter what the cost.

"I understand," she said, her voice cracking on the words. "Thank you, Nanaki."

Nanaki bumped his nose against her knee. "Tifa, I know that this journey will be more difficult for you than I could ever imagine. Please know that I will be here for you, every step of the way. We _will_ find out what happened to Nibelheim. I swear it, on my honor as the son of Seto."

Tifa smiled tightly, not trusting herself to speak, and cupped the back of Nanaki's head. He leaned into her touch, rumbling against her.


End file.
